1 /* $NetBSD: file.c,v 1.5 2011/02/16 18:35:39 joerg Exp $ */
2 /* $OpenBSD: file.c,v 1.11 2010/07/02 20:48:48 nicm Exp $ */
3
4 /*-
5 * SPDX-License-Identifier: BSD-2-Clause
6 *
7 * Copyright (c) 1999 James Howard and Dag-Erling Smørgrav
8 * Copyright (C) 2008-2010 Gabor Kovesdan <gabor@FreeBSD.org>
9 * Copyright (C) 2010 Dimitry Andric <dimitry@andric.com>
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <sys/param.h>
35 #include <sys/mman.h>
36 #include <sys/stat.h>
37 #include <sys/types.h>
38
39 #include <err.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <stddef.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <wchar.h>
47 #include <wctype.h>
48
49 #include "grep.h"
50
51 #define MAXBUFSIZ (32 * 1024)
52 #define LNBUFBUMP 80
53
54 static char *buffer;
55 static char *bufpos;
56 static size_t bufrem;
57 static size_t fsiz;
58
59 static char *lnbuf;
60 static size_t lnbuflen;
61
62 static inline int
grep_refill(struct file * f)63 grep_refill(struct file *f)
64 {
65 ssize_t nr;
66
67 if (filebehave == FILE_MMAP)
68 return (0);
69
70 bufpos = buffer;
71 bufrem = 0;
72
73 nr = read(f->fd, buffer, MAXBUFSIZ);
74 if (nr < 0 && errno == EISDIR)
75 nr = 0;
76 if (nr < 0)
77 return (-1);
78
79 bufrem = nr;
80 return (0);
81 }
82
83 static inline int
grep_lnbufgrow(size_t newlen)84 grep_lnbufgrow(size_t newlen)
85 {
86
87 if (lnbuflen < newlen) {
88 lnbuf = grep_realloc(lnbuf, newlen);
89 lnbuflen = newlen;
90 }
91
92 return (0);
93 }
94
95 char *
grep_fgetln(struct file * f,struct parsec * pc)96 grep_fgetln(struct file *f, struct parsec *pc)
97 {
98 char *p;
99 size_t len;
100 size_t off;
101 ptrdiff_t diff;
102
103 /* Fill the buffer, if necessary */
104 if (bufrem == 0 && grep_refill(f) != 0)
105 goto error;
106
107 if (bufrem == 0) {
108 /* Return zero length to indicate EOF */
109 pc->ln.len= 0;
110 return (bufpos);
111 }
112
113 /* Look for a newline in the remaining part of the buffer */
114 if ((p = memchr(bufpos, fileeol, bufrem)) != NULL) {
115 ++p; /* advance over newline */
116 len = p - bufpos;
117 if (grep_lnbufgrow(len + 1))
118 goto error;
119 memcpy(lnbuf, bufpos, len);
120 bufrem -= len;
121 bufpos = p;
122 pc->ln.len = len;
123 lnbuf[len] = '\0';
124 return (lnbuf);
125 }
126
127 /* We have to copy the current buffered data to the line buffer */
128 for (len = bufrem, off = 0; ; len += bufrem) {
129 /* Make sure there is room for more data */
130 if (grep_lnbufgrow(len + LNBUFBUMP))
131 goto error;
132 memcpy(lnbuf + off, bufpos, len - off);
133 /* With FILE_MMAP, this is EOF; there's no more to refill */
134 if (filebehave == FILE_MMAP) {
135 bufrem -= len;
136 break;
137 }
138 off = len;
139 /* Fetch more to try and find EOL/EOF */
140 if (grep_refill(f) != 0)
141 goto error;
142 if (bufrem == 0)
143 /* EOF: return partial line */
144 break;
145 if ((p = memchr(bufpos, fileeol, bufrem)) == NULL)
146 continue;
147 /* got it: finish up the line (like code above) */
148 ++p;
149 diff = p - bufpos;
150 len += diff;
151 if (grep_lnbufgrow(len + 1))
152 goto error;
153 memcpy(lnbuf + off, bufpos, diff);
154 bufrem -= diff;
155 bufpos = p;
156 break;
157 }
158 pc->ln.len = len;
159 lnbuf[len] = '\0';
160 return (lnbuf);
161
162 error:
163 pc->ln.len = 0;
164 return (NULL);
165 }
166
167 /*
168 * Opens a file for processing.
169 */
170 struct file *
grep_open(const char * path)171 grep_open(const char *path)
172 {
173 struct file *f;
174
175 f = grep_malloc(sizeof *f);
176 memset(f, 0, sizeof *f);
177 if (path == NULL) {
178 /* Processing stdin implies --line-buffered. */
179 lbflag = true;
180 f->fd = STDIN_FILENO;
181 } else if ((f->fd = open(path, O_RDONLY)) == -1)
182 goto error1;
183
184 if (filebehave == FILE_MMAP) {
185 struct stat st;
186
187 if (fstat(f->fd, &st) == -1 || !S_ISREG(st.st_mode))
188 filebehave = FILE_STDIO;
189 else {
190 int flags = MAP_PRIVATE | MAP_NOCORE | MAP_NOSYNC;
191 #ifdef MAP_PREFAULT_READ
192 flags |= MAP_PREFAULT_READ;
193 #endif
194 fsiz = st.st_size;
195 buffer = mmap(NULL, fsiz, PROT_READ, flags,
196 f->fd, (off_t)0);
197 if (buffer == MAP_FAILED)
198 filebehave = FILE_STDIO;
199 else {
200 bufrem = st.st_size;
201 bufpos = buffer;
202 madvise(buffer, st.st_size, MADV_SEQUENTIAL);
203 }
204 }
205 }
206
207 if ((buffer == NULL) || (buffer == MAP_FAILED))
208 buffer = grep_malloc(MAXBUFSIZ);
209
210 /* Fill read buffer, also catches errors early */
211 if (bufrem == 0 && grep_refill(f) != 0)
212 goto error2;
213
214 /* Check for binary stuff, if necessary */
215 if (binbehave != BINFILE_TEXT && fileeol != '\0' &&
216 memchr(bufpos, '\0', bufrem) != NULL)
217 f->binary = true;
218
219 return (f);
220
221 error2:
222 close(f->fd);
223 error1:
224 free(f);
225 return (NULL);
226 }
227
228 /*
229 * Closes a file.
230 */
231 void
grep_close(struct file * f)232 grep_close(struct file *f)
233 {
234
235 close(f->fd);
236
237 /* Reset read buffer and line buffer */
238 if (filebehave == FILE_MMAP) {
239 munmap(buffer, fsiz);
240 buffer = NULL;
241 }
242 bufpos = buffer;
243 bufrem = 0;
244
245 free(lnbuf);
246 lnbuf = NULL;
247 lnbuflen = 0;
248 }
249